John Domville wrote: > Lawrence G > Ok, I finally got around to running the test you suggested. The first > couple moves (test #1) up and down > Are ok, but after that the tip gets lower and lower into the piece. Also > the motor makes a binding noise just > Before it starts screwing up. Sounds like the motor is trying to move two > opposite directions at the same time. > Never did get to test two. So where do we go now? This by the way is with > a config file that uses + as a Z axis up > And - as a Z axis down. Had a pencil stub loosely in the collet during the > test and it kept getting pushed further and further > Into the collet until I forced a stop to the program before the face of the > collet went in to the bed surface. > Well, any time you are losing position with the Z axis dropping lower and lower, you have to look at the capability of the motor to raise the head. if you are overloading the motor due to the weight of the head, then it will lose steps when moving up. I'm assuming this is a machine with a milling head or router that is raised by the motor, not a machine with a lightweight quill.
First thing to try is to run the same program at lower speed (try 50% feed override, then 25%, then 10%). If it works OK at lower speed, that is an indication that your steppers can't deliver the torque needed for upward movement PLUS acceleration at that velocity. (Steppers are stronger, generally, at lower speeds.) You may have to lower the maximum velocity setting in your .ini file to whatever the machine can reliably do. If the head is very heavy, you may have to go with a stronger stepper motor, or go to a 2:1 belt reduction ratio to get more torque at the leadscrew. Jon ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
